The present invention concerns a ski brake, i.e., a device intended to prevent a ski from sliding down a slope if, a safety binding having become undone in the course of a descent, the ski is no longer attached to the skier. A device of this kind therefore replaces the safety bindings at present in use.
Such a device generally comprises a kind of "spike" or sideways brake arms which by means of spring pressure project downwards from the base of the ski as soon as the binding loosens and the ski boot is removed therefrom. The spike or brake arms thereupon more or less penetrate the snow, the ski comes to a halt on the slope and the skier can easily recover it. There is therefore no risk of the ski descending the slope and either injuring skiers further down or of becoming lost.
In known devices of this kind, their action is basically dependent on a torsion spring coiled round the transverse fixed shaft round which the spike or brake arm rotates. This arrangement is not particularly advantageous since the spring is fully extended when it forces the arm to project from the base of the ski: as a result the spring can offer only very feeble resistance to a displacement of the arm which can be easily pushed back by obstacles it comes up against before the ski stops. It is therefore obvious that if the arm retracts when it encounters obstacles the braking effect is not as efficient as it could be.
Moreover, once the boot is removed the brake arm or arms situated at the side of the ski project permanently from the underside of the ski, which makes transport of the ski awkward. To remedy this inconvenience, a bolt arrangement has been devised which immobilizes the arm or arms on the ski during transport. This solution is not ideal, however, since while it eliminates one inconvenience it introduces another, this being the risk of forgetting to undo the bolt when ski-ing commences. Once the boot is freed owing to a fall, the blocked brake cannot therefore function and the ski will set off by itself down the slope. Further, as this bolt is situated below the boot, it is not subject to visual control.
The general object of the present invention is to remedy these inconveniences by proposing a ski brake comprising an activating system of such construction that the spring is not completely extended in its operative position, i.e., when the brake arm or arms project from the base or underside of the ski.